Ensuring the increased requirements for heat saving, environmental safety and comfort of residential and public buildings is one of the main directions of scientific and technological progress in construction. In particular, the cellular concrete products’ use in building envelopes is aimed at solving these problems. Cellular concrete blocks perform the wall-forming material functions and insulation simultaneously due to their thermophysical and strength characteristics. However, the factor reducing the energy efficiency of aerated concrete masonry is the filling of masonry joints with adhesive or cement-sand mortar, which are the thermometer bridges, and the use of polyurethane adhesive, which has lower thermal conductivity compared to adhesive mixtures, as an aggregate of vertical and horizontal joints is unacceptable due to its high deformability and low shear stiffness. The authors examined the systems of building envelopes made of cellular concrete blocks used in civil engineering, and identified their shortcomings that affect the energy efficiency of the entire building. The authors have developed an energy-efficient two-row masonry of cellular concrete blocks, the device of which allows to reduce the masonry thickness and facilitate the installation of the enclosing structure with equal masonry thermal conductivity.
The efficiency of porous structure formation in aerated concrete can be improved by including the methods of thermal vacuum compaction or thermal vacuum compaction with vibration into the process as a means of creating high-quality composite cellular concrete. A graphic model of a phase composition change in the aerated concrete mix was developed allowing for an evaluation of the recipe and the mode of bubble porosity generation during hardening. This provides a control over the manufacturing processes and helps to produce aerated concrete with the specified porosity balance, which defines product properties.The effect of temperature and vacuum on molding sand during the initial stage of manufacture is proportional to the bubble porosity volume, which is important for a high-quality porous structure formation. In addition to the above, account must be taken of the combined effect of temperature, vacuum and volume ratio of phases in the base mix when using the proposed methods.Introduction of the developed processing methods into the manufacturing process improves the technology of aerated concrete production and allows for a fabrication of the finest advanced heat insulating and structural and heat insulating products.
Suleymanova L.A., Pogorelova I.A., Marushko M.V., Ognev N.V. VIBRO-VACUUM GYPSIFEROUS COMPOSITES Porous structure of concrete can be got not only by gassing, but also from correct Rayleigh Plesset equationby factor of external pressure. Vibration-vacuum method of aeration of forming mixes allows to get wide gamma of effective building materials with porous structure, one of which is expanded gypsum concrete.